Royal Society, 89 



acid ; and entered into various new views connected with 

 chemical theory. 



Potassium burns, as Mr. Davy discovered, in fluoric acid 

 gas, and separates its hosts, which combines with the potash 

 formed, or with the potassium, if this last be in excess; and 

 this compound of the fluoric basis, and the alkali or alka- 

 line basis, produces fluate of potash by combustion, or by 

 the action of water. 



Common muriatic acid gas, Mr. Davy has discovered, con- 

 tains at least a third of its weight of water. Mr. D. has not 

 been able to procure it free from water in an uncombined 

 state ; but he has obtained combinations of muriatic acid 

 with phosphorous acid, phosphoric acid, sulphuric acid, and 

 with phosphorus, free from moisture; and these compounds, 

 even when fluid, though constituted by matter supposed to 

 be intensely acid, do not act on litmus paper nor dissolve 

 alkalis, and are non-conductors of electricity ; but a very 

 small quantity of water develops their energies, renders them 

 conductors, and makes them capable of violently acting 

 upon litmus and alkaline bodies. With these compounds 

 of muriatic acid, potassium detonates violently even at com- 

 mon temperatures. The energy of the explosion has hitherto 

 prevented Mr. Davy from examining the results ; but he 

 thinks it probable that the muriatic acid may undergo change 

 or decomposition in the experiment. 



In the course of his general inquiries Mr. Davy examined 

 an experiment, (lately published in Mr. Nicholson's Journal) 

 on the production of ammonia, from a pyrophorus moist- 

 ened with water, by Professor Woodhouse; and states that 

 he has found his results Accurate; but that the formation of 

 the volatile alkali depends upon nitrogen absorbed from the 

 atmosphere by the charcoal employed. 



Mr. Davy, by exposing the pyrophorus whilst cooling 

 to hydrogen gas, found that no ammonia could then be pro- 

 duced by the affusion of water. 



Mr. Davy, from experiments made upon a large scale, 

 confirms his former analysis of potash, as consisting of about 

 1 4 of oxygen to 86 of metal. 



He defends the theory of Lavoisier against the opinions of 



some 



